The Benefits of Interactive Prototyping

I had a small epiphany today while working on a new prototype for a client: “different stages of prototyping yield different levels of information”. I know I know, not much of a brainwave there, right? I was never one for writing headlines and there’s a lot of knowledge packed into that statement, so stick with me as I attempt to unpack it for you 🙂

The Gist

Those familiar with it will know there are some basic ways to prototype that progress upwards in terms of fidelity. At the lowest end of the fidelity spectrum people often start by drawing lots of boxes and arrows on paper. Next comes some of the static mockup tools that are popular today, like Balsamiq, Hot Gloo, Fireworks (and many more). Further up the fidelity chain comes prototyping in the Browser which has some interesting advantages over static prototypes; what struck me today was how much more I could learn from prototyping in the browser when I moved from static markup into interactivity. Each level of fidelity provides different things we can learn; at a high level this is how I think it breaks down:

Paper Prototyping

What I think the information architecture hierarchy should be.

Static Prototyping

How I think the information architecture hierarchy will flow from one area to another.

Browser Prototyping (Static)

How the information hierarchy actually flows from one area to another at different screen resolutions.

How changes in typography, size, and placement affect the usability of my information architecture.

Browser Prototyping (Interactive)

How robust the information architecture and design are when considering user interaction.

What things I should do first to improve my information architecture and design.

As I read through the list above I notice a few interesting things. Firstly, the value of the information I receive increases as I move to a higher fidelity prototype. In Paper and Static prototyping the information I get isn’t really all that useful; for the most part it is hypothetical. I can show it to others to get more feedback but it is still subjective; based on perception and varied interpretation. It isn’t until I move into prototyping with the Browser that I can actually play with the information, architecture, and layout and start to get concrete information that will help me approach what I need to change in my next iteration.

In Practice

The interface and interaction I have been prototyping the last two days is for a user creating a fitness challenge comprised of multiple activities for multiple participants. As I was working to take my browser prototype from static to interactive I discovered that even though I had a good idea of how the system I was implementing worked I found I didn’t have a great way to express the system thinking in a user interface that made sense to humans.

So often engineers have a great grasp on what the system requirements are for the interface they are building that they end up building the interface as if it reads like machine language. In the last two days I feel it was very valuable to repeatedly try to express the system constraints in “plain old english” as if I were a user trying to interact with them, but I didn’t come to that realization until I made the leap from static to interactive.

In my first pass at the prototype with static content and no interaction this is what I came up with. The interaction theory was that users would fill in basic details about the fitness challenge and be able to see a preview summary of what the challenge would look like before submitting to the server(you can see the summary at the bottom of the screen). During this iteration I came to the realization that that positioning the summary at the bottom of the screen does nothing to help users understand what it is they are doing; we ended up deciding on a new layout that positions the summary to be always in the users view in the following iteration.

In this iteration the idea for a “live updating” summary was the driver for the layout change. We thought that if users could see the results of their interaction taking shape live it would help to reinforce how the interface was affecting the output (challenge creation).

Because one of our design constraints was to attempt to make this page work for both desktop and mobile we implemented the twitter bootstrap responsive stylesheet so we could play with the layout and see how it felt. This is one of the biggest benefits of designing in a browser first and previewing the design in the iOS simulator really helped to further shape the layout. Up to this point we were still iterating with static markup and felt like we were making good progress with the information we had received from in browser testing. The next step was to start wiring up user interactions to see what else was revealed.

I’ve been using Backbone.JS for the last 18 months and it’s a wonderful tool for building prototypes with. We decided to add some simple collection backed views and flesh out the user interaction of adding Activities and having them update live in the preview. What this yielded first was a realization that our design didn’t account for all that many rules due to our fixed position summary preview. (note: the new affix plugin in bootstrap 2.1 is _great_ for this, but you should be aware of how tall your content could potentially be!)

Oops. You could say I should have encountered that in the static stage of in browser testing by adding more static data to test the layout, but I didn’t and I find that this is often the case with static prototypes. Adding interactivity to a prototype helps to uncover places your design breaks down. It was at this point I had a discussion with a teammate to demo what had been built so far and we both came to the realization that the tabular display under the activities UI was not user friendly. The interface for adding Activities seems to read like english (we arrived at that after a number of iterations) but the display of the data isn’t helpful to users at all and really mirrors how the underlying system stores the data.

Moving Forward

Our next step will be to prototype a layout where the summary preview _is_ the interface to eliminate the “system language” from the interface altogether. In conclusion, I don’t think we would have been able to iterate and refine our approach as effectively if we had not started in the browser and added interactivity to the prototype soon after prototyping with static markup. The things we can learn from interactive prototypes can really help crank out interfaces that are much more usable.

If you aren’t already prototyping interactivity in the browser I would encourage you to start as soon as possible, the earlier you start the earlier you’ll find out how to fix your interface! 🙂